Adjustable scaffold leg unit



Sept. 4', 1956 R. COTTAR ADJUSTABLE SCAFFOLD LEG UNIT Filed July 22, 1955 INVENTOR Q0591? C'ozzaz' BY Arm .5.

United States Patent ADJUSTABLE SCAFFOLD LEG UNIT Robert Cottar, Red Blulf, Calif.

Application July 22, 1955, Serial No. 523,890

3 Claims. (Cl. 304-) This invention relates to, and it is a major object to provide, a novel supporting leg unit for a low-level scaffold plank as used-for examp1e-by carpenters, painters, or plasterers.

Another important object of the present invention is to provide a supporting leg unit, for the purpose described, which is strong but light weight, adjustable to selective heights, and readily manually foldable to a compact position when not in use and to permit of convenient movement, either on or off the scaffold plank, from place to place.

An additional object of the invention is to provide a scafiold plank supporting leg unit which is stable and safe when in use.

It is also an object of the invention to provide a scaffold plank supporting leg unit which is designed for ease and economy of manufacture, and for ready mounting on, or removal from, the plank.

Still another object of the invention is to provide a practical and reliable adjustable scaffold leg unit, and one which will be exceedingly effective for the purpose for which it is designed.

These objects are accomplished by means of such structure and relative arrangement of parts as will fully appear by a perusal of the following specification and claims.

In the drawings:

Fig. 1 is a perspective view of a pair of the scaifold plank supporting leg units as in use; the plank being shown foreshortened.

Fig. 2 is an outer end elevation of one of the scafiold plank-supporting leg units as in use.

Fig. 3 is a longitudinal sectional elevation taken on line 3-3 of Fig. 2.

Fig. 4 is a side elevation of one of the scaffold plank supporting leg units; the same being shown in full lines in a position of relatively high adjustment, and in dotted lines in its folded position.

Fig. 5 is a fragmentary cross section on line 5-5 of Fig. 3.

Referring now more particularly to the drawings, and to the characters of reference marked thereon, a pair of the supporting leg units, each of which is indicated generally at 1, are used at longitudinally spaced points on, and to support, a scaffold plank 2 at a selected height above-floor. The scaffold plank supporting leg units, while used in opposition on the scaffold plank 2, are iden tic-a1 in constructionhence a description of one will suffice for both.

Each scaiiold plank supporting leg unit 1 comprises an outer slotted cross head 3 and an inner slotted cross head 4 disposed in longitudinally spaced relation; said cross heads 3 and 4 being disposed in alinement, and all in the form of sleeves adapted to receive the scaffold plank therethrough in close fitting but slidable relation.

At the ends thereof the slotted cross heads 3 and 4 are formed with integral depending attachment brackets, indicated at 5 and 6, respectively.

A pair of transversely spaced, downwardly and outwardly inclined and divergent legs 7 are pivoted at their upper ends, as at 8, on the corresponding depending brackets 6 of theinner cross head 4; such legsintermediate their ends-being connected together in rigid unitary relation by an integral cross bar 9.

A pair of transversely spaced diagonal thrust links 10 are pivoted at their ends, as at 11, to the corresponding depending brackets 5 of the outer cross head 3; such thrust links thence extending at a downward and inward incline to pivotal connection at their lower ends, as at 12, to the related legs 7 substantially centrally of the ends of the latter.

A longitudinal stay bar 13 extends between the cross heads 3 and 4 in a plane below the same, and said stay bar is pivoted at its outer end, as at 14, between a pair of ears 15 which depend from the bottom of the cross head 3 substantially centrally of its ends.

The longitudinal stay bar 13 is formed with a row of longitudinally spaced, downwardly opening notches 16 therein, and which notches are inclined toward their open ends in the same direction as the incline of the legs 7. The longitudinal stay bar 13 is of such length that it projects inwardly, lengthwise of the plank 2, a distance beyond the inner cross head 4, and said stay barintermediate its ends-passes between a pair of cars 17 which depend, in transversely spaced relation, from said inner cross head 4 substantially centrally of its ends.

A cross pin 18 connects the ears 17 adjacent the bottom thereof, and the stay bar 13 passes between said ears 17 above such cross pin; this to the end that said cross pin may be selectively engaged in any one of the notches 16, and so that the stay bar then prevents any separation of the cross heads 3 and 4 in 'a longitudinal direction.

When each scaffold plank supporting leg unit, as above described, is in use the cross heads 3 and 4 are first slid onto an end portion of the scaffold plank 2, and at which time said cross heads are in longitudinally spaced relation. Thereafter, the stay bar 13 is adjusted in its effective length by setting the cross pin 18 in a selected notch 16, and which adjustment of course effects a corresponding setting of the legs 7 to a position supporting the scaffold plank 2 at a desired height.

After the stay bar 13, and legs 7, are adjustedas abovethe outer cross head 3 is secured against longitudinal displacement on the scaffold plank 2 by means of headed nails 19 driven into the side edge portions of said plank through holes 20 provided in both ends of said outer cross head 3. The nails 19 are not fully driven, so that they may be easily pulled when it is desired to remove the leg unit from the scaffold plank.

With a pair of the described supporting leg units used in opposition on a scaffold plank 2 in the manner shown in Fig. 1, such plank is effectively supported in a stable position from the floor and for use by the Workman at a selected height; the outward and downward incline, together with the divergence of the legs 7, enhancing such stability.

In Fig. 4 the scaffold plank supporting leg unit is shown as adjusted to its maximum height, and to prevent the legs 7 from passing beyond vertical or dead-center, a transverse limit pin 21 is secured to the stay bar 13. Such limit pin 21 prevents the inner cross head 4 from approaching the outer cross head 3 close enough to permit the'legs 7 to undesirably pass over dead-center.

When the scaffold plank 2 is not in use, and it is desired to transport it from place to place, the supporting leg unitsl can be readily manually folded to the dottedline position shown in Fig. 4 by simply releasing the notched stay bar 13 from the cross pin 18, which permits the inner cross head 4 to slide inwardly on the plank 2, and the legs 7 and thrust links 10 to fold in the direction of said plank. Such folding of each supporting leg unit can likewise be accomplished when the unit is detached from the scaffold plank.

From the foregoing description it will be readily seen that there has been produced such a device as will substantially fulfill the objects of the invention, as set forth herein.

While this specification sets forth in detail the present and preferred construction of the device, still in practice such deviations from such detail may be resorted to as do not form a departure from the spirit of the invention, as defined by the appended claims.

Having thus described the invention, the following is claimed as new and useful, and upon which Letters Patent are desired:

1. A scaffold plank supporting leg unit comprising a pair of cross heads adapted to engage the plank in supporting and slidable relation and at longitudinally spaced points, a pair of transversely spaced legs connected at their upper ends to one cross head and thence extending downwardly at an incline for floor engagement, a pair of transversely spaced diagonal thrust links connected at their upper ends to the other cross head and at their lower ends to the legs intermediate the ends of the latter, all of the leg and link connections being pivotal, a longitudinal stay bar extending between the cross heads, and means connecting the stay bar to said cross heads in normally longitudinally rigid relation but for adjustment of the effective length of said stay bar.

2. A unit, as in claim 1, in which the cross heads are in the form of sleeves in which the plank slidably projects; said other cross head having means for releasable holding engagement with the plank.

3. A scafiold plank supporting leg unit comprising a pair of cross heads in the form of sleeves adapted to receive the plank therethrough and disposed at longitudinally spaced points thereon, a pair of transversely spaced legs pivoted at their upper end to one cross head at the sides thereof and extending thence downwardly at an incline in the direction of .the other cross head for floor engagement, a pair of transversely spaced diagonal thrust links pivoted .at their .upper end on the other cross head and at their lower end on the legs intermediate the ends thereof, a longitudinal substantially horizontal stay bar extending between the cross heads, means pivoting the stay bar at one end on one cross head under the same for swinging in a vertical longitudinal plane, there being a row of longitudinally spaced downwardly opening notches in the stay bar intermediate its ends, ears depending from the other cross head in alinement with the stay bar and spaced apartto receive said bar therebetween,

and across pin mounted in the ears a distance below said other cross head greater than the vertical width of the stay bar whereby the latter may be slid lengthwise so that a selected notch may be disposed above the cross pin and the stay bar then lowered to engage such notch with said cross pin.

References Cited the file of this patent UNITED STATES PATENTS 

